<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title> css </title>
    <!-- rel使用外部样式表 href文件路径 -->
    <link rel="stylesheet" href="01.css">
    <!-- <style> 
        h1{
           color: red;
           font-size: 60px;
    }
    </style>-->
    
</head>
<body>
    <!-- <h1 style="color:aqua">你好</h1> -->
    <h1>你好</h1>
</body>
</html>